Building a custom home is the one chance to get the electrical system planned right from the studs out, not patched together after the fact. Mercanti Electric provides custom home electrical hamilton homeowners and builders can plan a whole house around, from initial load design through final inspection.
Custom home electrical hamilton projects are fundamentally different from a renovation, because there’s no existing wiring to work around and no compromises forced by what’s already behind the walls. That’s an advantage, but only if the electrical scope is actually planned for the home you’re building, not treated as an afterthought once framing is done. Panel sizing, circuit layout, smart home infrastructure, and code requirements around EV readiness and alarm systems all need to be decided early, since retrofitting any of them after drywall is up costs significantly more than building them in from the start.
Mercanti Electric is the custom home electrical hamilton homeowners and builders rely on, handling the full electrical scope from initial load calculations through rough-in, trim-out, and final ESA inspection. Joseph Mercanti brings 13 years of electrical experience and full ESA/ECRA licensing (#7017086) to every build, so the finished home’s electrical system is planned properly, not assembled as decisions come up on-site.
Every custom home has a different electrical load depending on its size, the systems it includes, and how the homeowner plans to use it. We calculate the actual load your home will draw rather than defaulting to a generic new-build spec, so the panel and service size fit the home you’re actually building. For larger builds, this is also where we confirm early whether a 200 amp or 400 amp service makes sense given your home’s full scope.
A generation ago, 100 amp service was standard for a new home. That’s no longer realistic for most custom builds, and it’s not just a preference, it reflects how much more electrical load a modern home actually carries. Between central air, EV charging, electric appliances, home offices, and increasingly common additions like hot tubs or backup generators, a 200 amp service has become the practical baseline for new construction, giving the home enough headroom to add major loads later without a service upgrade.
Sizing this correctly at the planning stage matters more in a custom build than almost anywhere else, because the panel location, conductor sizing, and service entrance are all decided before walls close, and getting it wrong means a genuinely disruptive fix later rather than a simple swap. We calculate your home’s actual anticipated load, including any known future additions like a hot tub or generator, before finalizing service size, so the panel installed at rough-in is sized for the home you’re actually going to live in, not just the minimum the code allows today.
Ontario has moved back and forth on whether new homes are required to include EV charging rough-in. Provincial legislation to mandate it, most recently the proposed EV-Ready Homes Act, has been introduced but has not been enacted into law as of this writing, so it isn’t currently a blanket provincial requirement for every new custom home. That said, several municipalities, including standards adopted in parts of the GTA, already require EV-ready wiring in new residential construction independent of the provincial requirement, and Ontario’s current electrical code has separately made it easier to size a home’s demand load correctly for future EV charging under revised Rule 8-106.
Regardless of what’s strictly required in your specific municipality, building in a dedicated conduit path and panel capacity for a future EV charger during construction costs a small fraction of what it costs to retrofit the same thing into finished walls and a poured driveway later. We include this in our custom home electrical planning as a standard recommendation, whether or not your specific municipality currently mandates it.
New construction has the strictest smoke alarm requirements in Ontario, and it’s worth understanding exactly what that means before your builder starts hanging drywall. Since January 1, 2015, the Ontario Building Code has required interconnected, hardwired smoke alarms with battery backup and a visual strobe component in every bedroom, on every storey, and outside every sleeping area for new homes, meaning an alarm triggered anywhere in the house sounds everywhere in the house simultaneously. This isn’t a minimum you can scale back on for a custom build, it’s the current baseline for any new dwelling, and if your build includes a secondary suite or ADU as part of the plan, interconnection requirements extend across both units.
Because this wiring needs to run through the home’s structure during rough-in, it has to be planned alongside your lighting and outlet circuits, not treated as a separate, later addition. We plan alarm interconnection as part of the same rough-in pass as the rest of your electrical system, so it’s fully integrated rather than added as an afterthought.
We review your home’s design, size, and planned systems to calculate the actual electrical load and appropriate service size.
We plan panel location, circuit layout, and any smart home or future-ready infrastructure before framing locks those decisions in.
We run all wiring for lighting, outlets, dedicated circuits, alarms, and any structured cabling, coordinated with your build schedule.
We coordinate the ESA rough-in inspection before insulation and drywall close up the walls.
Once drywall and finishing are complete, we install fixtures, switches, outlets, and devices throughout the home.
We test the complete system and coordinate the final ESA inspection, providing documentation for your records and your builder’s file.
A poorly planned custom home electrical scope tends to reveal itself well after move-in, when a homeowner discovers the panel doesn’t have room for the EV charger they wanted, or the alarm system wasn’t properly interconnected. Watch for an electrician who sizes the service to the bare code minimum without discussing your actual anticipated load, or who treats EV readiness and smart home wiring as an upsell rather than a planning conversation at the start of the project. A proper custom home electrical scope includes a documented load calculation, panel sizing based on your home’s real needs, correctly interconnected alarms, and both a rough-in and final ESA inspection with documentation you can keep on file.
Mercanti Electric provides custom home electrical services throughout:
Get the custom home electrical hamilton builders trust, planned right from the start, not patched together on-site.
200 amp service has become the practical standard for new construction, given modern loads like central air, EV charging, and larger appliance packages. Your specific load calculation may support a different size depending on your home’s design.
Not provincially, as of this writing. Legislation to mandate it has been introduced but not enacted, though some municipalities already require EV-ready wiring independently. We recommend building it in regardless, since retrofitting later is far more disruptive.
Yes. Since January 1, 2015, Ontario’s Building Code has required interconnected, hardwired smoke alarms with battery backup and a strobe component in every bedroom, on every storey, and outside every sleeping area of new construction.
As early as possible, ideally during the design phase before framing is finalized, since panel location, service size, and rough-in decisions are much harder and more expensive to change once walls are up.
Yes. We coordinate directly with builders and general contractors on custom home projects, working within the overall construction schedule rather than requiring you to manage electrical scheduling separately.
Yes. New construction requires an ESA electrical permit, along with a rough-in inspection before walls close and a final inspection before the home is occupied.
It’s worth discussing during planning. Building in appropriate panel capacity or conduit paths now is significantly cheaper than adding them to a finished home later.
